\\[-1.8ex] Soil Heterogeneity & $-$1.207$^{***}$ & $-$1.207$^{***}$ & $-$0.673$^{***}$ & $-$0.472$^{**}$ & $-$0.316$^{*}$ & $-$0.458$^{***}$ \\ 
  & (0.288) & (0.288) & (0.231) & (0.205) & (0.161) & (0.154) \\ 
\\[-1.8ex] 
Observations & 21,671 & 21,671 & 21,671 & 21,671 & 21,671 & 21,612 \\ 
R$^{2}$ & 0.018 & 0.018 & 0.353 & 0.430 & 0.446 & 0.462 \\ 
